Angular 订阅IONIC2提供程序与页面和自定义组件不同步

这是我的可订阅购物车提供商，其中

.Cart

是可订阅的

@Injectable()
export class CartProvider {

  cart: Observable<Array<CartItem>>
  private _cart: BehaviorSubject<Array<CartItem>>;
  private cartStore: Array<CartItem> = [];

  constructor(private dialogs: DialogsProvider) {
    this._cart = <BehaviorSubject<Array<CartItem>>>new BehaviorSubject([]);
    this.cart = this._cart.asObservable();
  }

  /**
   * return obs array cart
   * 
   * @returns {Observable<Array<CartItem>>} 
   * @memberof CartProvider
   */
  getCart(): Observable<Array<CartItem>> {
    return this.cart;
  }

---

更新：：

我通过像这样将CartProvider添加到CustomComponent providers数组中解决了这个问题

import { NgModule } from '@angular/core';
import { IonicPageModule } from 'ionic-angular';
import { CartComponent } from './cart';
import { CartProvider } from "../../providers/cart/cart";

@NgModule({
  declarations: [ 
    CartComponent,
  ],
  imports: [
    IonicPageModule.forChild(CartComponent),
  ],
  exports: [
    CartComponent
  ],
  providers:[
    CartProvider // <-------- added here instead of adding it to component.providers array
  ]
})
export class CartComponentModule {}

从'@angular/core'导入{NgModule}；
从“离子角度”导入{IonicPageModule}；
从“./cart”导入{CartComponent}；
从“./../providers/cart/cart”导入{CartProvider}”；
@NGD模块({
声明：[
CartComponent，
],
进口：[
IonicPageModule.forChild（CartComponent），
],
出口：[
CartComponent
],
供应商：[
CartProvider//
    <button ion-button clear icon-only (click)="showCart()">
        <ion-icon name="cart"></ion-icon>
        <span class="badge" *ngIf="cartDisplay > 0">{{cartDisplay}}</span>
    </button>

import { NgModule } from '@angular/core';
import { IonicPageModule } from 'ionic-angular';
import { CartComponent } from './cart';
import { CartProvider } from "../../providers/cart/cart";

@NgModule({
  declarations: [ 
    CartComponent,
  ],
  imports: [
    IonicPageModule.forChild(CartComponent),
  ],
  exports: [
    CartComponent
  ],
  providers:[
    CartProvider // <-------- added here instead of adding it to component.providers array
  ]
})
export class CartComponentModule {}